LOCATION PROTIVIN IA+MNEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquic Argiudolls
TYPICAL PEDON: Protivin loam, on a west-facing, plane, 1 percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; weak fine granular structure; friable; strongly acid; clear smooth boundary.
A1--8 to 11 inches; black (10YR 2/1) loam, dark gray (10YR 4/1) dry; moderate fine granular structure; friable; strongly acid; gradual smooth boundary.
A2--11 to 15 inches; very dark gray (10YR 3/1) and very dark grayish brown (10YR 3/2) loam, very dark grayish brown (10YR 3/2) kneaded, gray (10YR 5/1) and grayish brown (10YR 5/2) dry; weak medium subangular blocky structure; friable; strongly acid; gradual smooth boundary. (Combined thickness of the A horizons is 12 to 20 inches.)
BA--15 to 19 inches; dark grayish brown (2.5Y 4/2) loam; weak fine subangular blocky structure; friable; few discontinuous very dark gray (10YR 3/1) coatings on peds; common fine distinct yellowish brown (10YR 5/4) redox concentrations; moderately acid; clear smooth boundary. (0 to 8 inches thick)
Bw--19 to 23 inches; olive brown (2.5Y 4/4) and dark grayish brown (2.5Y 4/2) loam; weak medium prismatic structure parting to weak fine subangular blocky; friable; many dark grayish brown (2.5Y 4/2) coatings on peds; pebble band in lower part of horizon (pebbles vary from 1/4 to 11/2 inches in diameter); common fine distinct yellowish brown (10YR 5/6) redox concentrations; moderately acid; clear smooth boundary. (0 to 6 inches thick)
2Bt1--23 to 34 inches; mottled strong brown (7.5YR 5/6) and gray (5Y 5/1) clay loam; moderate medium prismatic structure parting to moderate medium fine subangular blocky; very firm; gray colors most evident on faces of prisms; few thin discontinuous very dark gray (N 3/0) clay films on faces of peds, in pores and root channels; few pebbles; slightly acid; gradual smooth boundary.
2Bt2--34 to 40 inches; mottled strong brown (7.5YR 5/6) and gray (5Y 5/1) clay loam; moderate medium prismatic structure parting to weak medium subangular blocky; very firm; gray color most evident on faces of prisms becoming less distinct with depth; few thin discontinuous very dark gray (10YR 3/1) clay films on faces of prisms, in pores and root channels; few pebbles; neutral; gradual smooth boundary.
2Bt3--40 to 45 inches; mottled gray (5Y 5/1), yellowish brown (10YR 5/6), and strong brown (7.5YR 5/6) clay loam; weak medium prismatic structure parting to weak medium subangular blocky; very firm; very few moderately thick streaks of very dark gray (10YR 3/1) clay on faces of prisms; few pebbles; slightly alkaline; clear wavy boundary. (Combined thickness of the 2Bt horizons is 18 to 34 inches.)
2C--45 to 60 inches; mottled gray (5Y 5/1), yellowish brown (10YR 5/6), and strong brown (7.5YR 5/6) clay loam; massive; firm; some vertical cleavage faces in upper part; common pebbles; very few prominent reddish brown (5YR 4/4) oxide concretions; slightly effervescent; slightly alkaline.
TYPE LOCATION: Howard County, Iowa; about 1/2 mile east and 3 miles north of the town of Saratoga; located about 1700 feet west and 63 feet south of the northeast corner of sec. 9, T. 99 N., R. 13 W.; USGS Lime Springs NW quad; lat. 43 degrees 24 minutes 59.6 seconds N. and long. 92 degrees 22 minutes 57.0 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: Depth to carbonates ranges from 40 to more than 60 inches. The particle-size control section contains 28 to 35 percent clay and 30 to 45 percent sand. Rock fragment content is 2 to 10 percent.
The A horizon has hue of 10YR, value of 2 or 3 and chroma of 1 or 2. Textures include loam, silt loam or clay loam. Clay content is 20 and 30 percent. Sand content is 20 to 35 percent. Reaction ranges from strongly acid to neutral. Some pedons have an AB horizon.
The Bw horizon has hues of 10YR or 2.5Y, value of 4 and chroma of 2 to 5. Textures include loam, clay loam, silty clay loam, or silt loam. Clay content is 20 to 30 percent. Sand content is 15 to 35 percent. Texture at the contact between the Bw and 2Bt horizons ranges from loam to sandy loam containing many small stones and pebbles. Reaction ranges from strongly acid to neutral.
The 2Bt and 2BC or 2C horizons have hues of 7.5YR to 5Y, value of 4 to 6 and chroma of 1 to 8. Textures include loam and clay loam. Clay content is 28 and 35 percent. Sand content is 30 to 45 percent. In some pedons there are vertical, elongated wedges of sandy loam to sand with an apex in the 2Bt or 2BC horizon that spread out to 2 to 12 inches in the 2C horizon. There are lenses or pockets of sand in the till in some pedons. Moist bulk density ranges from 1.6 to 1.7 gm/cc. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: These are the Andres, Aztalan, Darroch, Francesville, Gilboa, Howstenander, La Hogue, La Hoguess, Le Sueur, Marcellon, Nachusa, Nenno, Newhaven, Odell, Vigar, and Wilmer soils. Andres soils contain less than 20 percent sand in the lower part of the series control section. Aztalan soils contain 18 to 27 percent clay in the particle-size control section. Darroch soils contain less than 20 percent clay in the lower part of the series control section. Gilboa soils contain 15 to 22 percent clay in the lower part of the series control section. Francesville soils have limestone bedrock within 60 inches. Houstenander soils contain 20 to 30 percent rock fragments in the particle-size control section. La Hogue soils contain 5 to 20 percent clay in the lower part of the series control section. Lahoguess soils contain 80 to 90 percent sand in the lower part of the series control section. Le Sueur soils have a moist bulk density range of 1.45 to 1.6 gm/cc in the lower part of the series control section. Marcellon soils contain 18 to 24 percent clay in the particle-size control section. Nachusa soils have a moist bulk density less than 1.6 gm/cc in the lower part of the series control section. Nenno soils have carbonates within 24 inches. Newhaven soils contain less than 15 percent clay in the lower part of the series control section. Odell soils contain 10 to 20 percent clay in the lower part of the series control section. Vigar soils have mollic epipedons ranging from 24 to 40 inches thick.
GEOGRAPHIC SETTING: Protivin soils formed in 14 to 28 inches of loamy sediments and the underlying glacial till of mixed mineralogical composition. Protivin soils are on long convex ridges and side slopes on uplands of the Iowan erosion surface. Slopes range from 0 to 5 percent. Elevation ranges from 650 to 110 feet. Mean annual temperature ranges from about 45 to 53 degrees F. Mean annual precipitation ranges from about 30 to 35 inches. Frost-free period ranges from 130 to 186 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cresco, Floyd, Jameston, Kenyon, and Lourdes soils. Cresco soils are moderately well drained and are on steeper slopes. Floyd soils do not have argillic horizons and are on similar positions. Jameston soils are poorly drained and are on toe slopes and in drainageways. Kenyon soils do not have argillic horizons and are on similar positions.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained--seasonal high saturation occurs within depths of 1.0 to 3.0 feet during April to June in normal years and is considered apparent. Surface runoff is medium. Permeability is moderate in the loamy sediments and moderately slow in the glacial till.
USE AND VEGETATION: Soils are cultivated. Corn, soybeans, small grains, and legume hays are the principal crops. Native vegetation is mixed prairie grasses.
DISTRIBUTION AND EXTENT: LRR M, MLRA 104; moderate extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Howard County, Iowa, 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface to 15 inches (Ap, A1 and A2 horizons); argillic horizon - the zone from 23 to 45 inches (2Bt1, 2Bt2 and 2Bt3 horizons); aquic subgroup based on matrix colors in zone from 15 to 23 inches (BA and Bw horizons); udic moisture regime. Cation exchange class is supported by lab samples. Taxonomic version - Second edition, 1999.
ADDITIONAL DATA: Laboratory data are available in the Soil Survey Investigations Report No. 3 for Iowa. Also, data obtained at the Iowa State University laboratory are in the file at Ames.